impact of quality of insulation on the performance … weidmann 2011_… · 2011. 11. 29. ·...

IMPACT OF QUALITY OF INSULATION ON THE PERFORMANCE OF TRANSFORMERS

MPOWERING ENERGY – Matelec 2011

DANIEL TSCHUDI

WEIDMANN A Member of the WICOR Group

ELECTRICAL TECHNOLOGY AG

IMPACT OF QUALITY OF INSULATIONCONTENT

1. Who is WEIDMANN2. Electrical insulation of transformers3. Quality aspects of transformer insulation4. Influence of insulation quality on the performance of transformers5. How does WEIDMANN assure the quality of insulation during the life q y g

of the transformer6. Conclusion

2

WE MAKE YOUR TRANSFORMERS BETTER

WHO IS WEIDMANNTRANSFORMERBOARD

1. WEIDMANN is worldwide‘s largest manufacturer of (solid) transformer insulation, operating 7 (5+2) Transformerboard machines and several component and paper manufacturing sites.

2. Transformerboard, the electric2. Transformerboard, the electric insulation material made from pure, unbleached Kraft pulp, was invented almost 75 years ago, by WEIDMANN (Hans Tschudi, 1937).(Hans Tschudi, 1937).

3. WEIDMANN facts and figures:Turnover: 605 / 390 Mio CHF Employees: 3630 / 2626

3

Employees: 3630 / 2626(Group / Electrical BA).

Transformerboard TIV


WHO IS WEIDMANN

1 O f WEIDMANN‘

MODULAR LEAD EXITS1. One of WEIDMANN‘s core

competence is the development and production of tailor-made insulation solutions from cellulose based materials and other eg high-materials and other, eg hightemperature insulation materials.

2. A modular design of lead exits, as invented by WEIDMANN, allows to y ,decrease throughput time and cost of this vital transformer component significantly.

3. In addition to transformer insulation components WEIDMANN produces a wide range of specialized insulation papers, eg. diamond dotted paper (DDP) for Distribution transformers

4

(DDP) for Distribution transformers.Modular 400 kV lead exit


WHO IS WEIDMANN

1 WEIDMANN ff it t

INTEGRATED ENGINEERING SERVICES1. WEIDMANN offers its customers,

transformer OEMs as well as transformer operators and users unique engineering services (electric, magnetic thermal field calculationsmagnetic, thermal field calculations, design reviews, static and dynamic analysis of networks and other Power system services, up to services related to Power electronics) to make their transformers and their operation more efficient and reliable.

2. WEIDMANN provides diagnostic services (eg oil analysis) and newly engineers and manufactures also transformer monitoring devices.

->to learn more please visit our booth

5

->to learn more, please visit our booth

Electric field calculation of a winding end design


ELECTRICAL INSULATION OF TRANSFORMERS

1 Th i i l i

OIL – CELLULOSE SYSTEM1. The most appropriate insulation

system for a transformer consists of cellulose based solid insulation (Transformerboard, papers etc.) and mineral oil or other insulation fluids. (These fluids are used for cooling the transformer too.)

2. Transformerboard and insulating papers as used in transformers consist of pure cellulose fibres (noconsist of pure cellulose fibres (no additives, glue etc). The poreous structures of the insulation materials allow for a complete impregnation with oil

6

with oil.Model of a Power transformer


QUALITY ASPECTS OF TRANSFORMER INSULATION (I)

1 Cl li (I) l i d

PRIMARY ASPECT: TO FULFIL AN INSULATION FUNCTION1. Cleanliness (I): -> selection and test

of raw material, eg conductivity, ash content, DP (Degree of Polymerisation), etc.

2. Cleanliness (II) -> screening of manufactured insulation:- in-line particle/hole detectionp- x-ray (voids)- geometrical stability

3 Avoid other foreign substances:3. Avoid other foreign substances:- as little glue as needed (voids etc.)- avoid sources of metal during manufacturing- avoid ingress of moisture

7

- avoid ingress of moistureX-ray of WEIDMANN Transformerboard


QUALITY ASPECTS OF TRANSFORMER INSULATION (I)

1 Cl li (I) l i d

PRIMARY ASPECT: TO FULFIL AN INSULATION FUNCTION1. Cleanliness (I): -> selection and test

of raw material, eg conductivity, ash content, DP (Degree of Polymerisation), etc.

2. Cleanliness (II) -> screening of manufactured insulation:- in-line particle/hole detectionp- x-ray (voids)- geometrical stability

3 Avoid other foreign substances:3. Avoid other foreign substances:- as little glue as needed (voids etc.)- avoid sources of metal during manufacturing- avoid ingress of moisture

8

- avoid ingress of moistureX-ray of a competitor‘s insulation material


QUALITY ASPECTS OF TRANSFORMER INSULATION (II)

1 T id h i l h

ADDITIONAL FUNCTIONS OF TRANSFORMER INSULATION1. To provide mechanical strength:

- achieve mechanical stability and strength with as little glue as needed.as needed.- avoid voids, when substantial glue is needed (laminated Transformerboard)

2. To endure thermal stress:- adequate design (as little solid insulation as needed avoidinsulation as needed – avoid thick insulation) to allow for smallest electrical gaps with optimal cooling.

9

p g

Seismic test of a 400 and 800 kV lead exit


QUALITY ASPECTS OF TRANSFORMER INSULATION (III)ADDITIONAL FUNCTIONS OF TRANSFORMER INSULATION

1. To age in a controlled way:- achieve a lifetime of the Transformerboard – oil i l ti t th t linsulation system that equals or exceeds that of the entire transformer.

the entire system oil- the entire system, oil-Transformerboard / paper needs to be examined and understood in aging tests.in aging tests.

10

Aging tests of different insulation fluids


INSULATION QUALITY - PERFORMANCE OF TRANSFORMERS (I)

1 M h i l bili

QUALITY IMPROVES VITAL FUNCTIONS1. Mechanical stability:

- withstand occasional short-circuit without physical change - withstand any transportationwithstand any transportation shocks without permanent movement / displacement- withstand an earthquake with

dno damage

2. Overloadability:- allow for a controlled overloadallow for a controlled overload without premature aging- insulation system may be designed specially (hybrid

t ) f l d bilit

11

system) for overload capabilityManufacturing of a Distribution transformer


1 U ti

QUALITY IMPROVES TOTAL COST OF APPARATUSINSULATION QUALITY - PERFORMANCE OF TRANSFORMERS (II)

1. Uptime:An acceptance test failure of a transformer due to a quality defect of its insulation leads to costly repair. A failure due to inadequate insulation

lit d i th ti f thquality during the operation of the transformer leads usually to expenses or losses exceeding the cost of the unit by far.

2. Long life:If the insulation system is not properly designed or if the quality of the materials used is otherwise insufficient (eg low DP due to excessive drying, no thermal uprating, etc.), local thermal hotspots, heat pockets or even regular service temperatures may lead to an accelerated end of life of the transformer.

12

Distribution transformer model


QUALITY OF INSULATION DURING TRANSFORMER LIFE (I)

1 P d i

WHAT DOES WEIDMANN DO: FROM DESIGN......1. Proper design:

The design of an insulation system is the foundation on which quality can be realized.Optimization of quality usually meansOptimization of quality usually means optimization of design first.

2. Proper manufacturing, handling, assembly:yThe transformer insulation has to be adequately protected - from moisture, foreign particles etc - during the manufacturing process until the insulation is finally assembled in theinsulation is finally assembled in the transformer. The remedies - plastic covers, a cleanliness discipline in the workshop etc - sound simple, but need to be observed and continuosly

13

to be observed and continuosly trained.

Design of a Faltenbalg protecting the transformerinterior from dust and moisture


QUALITY OF INSULATION DURING TRANSFORMER LIFE (II)

1 Di i d i i f

WHAT DOES WEIDMANN DO: TO DEMISE......1. Diagnostic and monitoring of

transformers:Condition assessment (of insulation) through diagnostics and selective (smart) monitoring assures a trouble-free operation of a transformer and helps predict and also prolong the end of its useful life.

2. Tear down analysis:A laboratory analysis of insulation y ysamples taken during a tear down (decomissioning) of a transformer is used to optimize future insulation systems.

14

insulation systems.

Insulogix H®, WEIDMANN‘s new hydrogen monitor detects this key fault gas


CONCLUSION

1 P l l d d

IT‘S ABOUT VALUE1. Properly selected and

controlled quality of insulation material and an adequate design of the insulation systemdesign of the insulation system are prime factors to improve the performance and to extend the lifetime of a transformer.

2. The value of a transformer, expressed through its total cost of ownership – measuredof ownership measured during the lifetime from design to demise of the unit - can be maximized by using quality i l ti

15

insulation.MATELEC transformers and Swiss gold coin


THANK YOU FOR YOUR ATTENTION !

16

impact of quality of insulation on the performance … weidmann 2011_… · 2011. 11. 29. ·...

Documents